Circuit Device, Electronic Apparatus, and Error Detection Method Using at Least an Index Indicating Similarity Between Foreground Image and Reference Image

1. A circuit device comprising: an image acquisition circuit configured to acquire an input image data; an image processing circuit configured to perform image processing on the input image data so as to combine the input image data with a reference image stored in a memory to obtain a composite image, the composite image being a display image; and an index acquisition circuit configured to obtain an index for performing error detection on the display image, wherein: the index acquisition circuit is configured to obtain the index representing a degree of matching between a foreground image, which is an image of a given region of the composite image including a region where the reference image has been composited onto the input image data, and the reference image stored in the memory; the index is obtained based on pixel values of the composite image and pixel values of the reference image or based on pixel values of an edge image of the composite image and pixel values of an edge image of the reference image; display of the display image is performed when the degree of matching between the foreground image and the reference image is equal to or greater than a threshold; and an error is determined when the degree of matching between the foreground image and the reference image is below the threshold.

2. The circuit device according to claim 1 , wherein the index is a shape index that evaluates a similarity between a shape of the foreground image and the reference image.

3. The circuit device according to claim 2 , wherein the foreground image is an image of an icon in the display image, and the reference image is a mask image.

4. The circuit device according to claim 1 , further comprising an index register for storing the index.

5. The circuit device according to claim 1 , further comprising an error detection circuit configured to perform the error detection on the display image based on the index, wherein the error is determined by comparing the index to the threshold.

6. The circuit device according to claim 1 , wherein the index acquisition circuit is configured to obtain an additional index that is separate and distinct from the index and that represents a degree of visibility of the foreground image against a background image of the display image, and the error detection on the display image is performed using both the index and the additional index.

7. An error detection method comprising: acquiring an input image data; generating a display image by performing image processing on the input image data so as to combine the input image data with a reference image stored in a memory to obtain a composite image, the composite image being the display image; and obtaining an index that represents a degree of matching between a foreground image, which is an image of a given region of the composite image including a region where the reference image has been composited onto the input image data, and the reference image stored in the memory, wherein: the index is obtained based on pixel values of the composite image and pixel values of the reference image, or based on pixel values of an edge image of the composite image and pixel values of an edge image of the reference image, the index is used for performing error detection on the display image; display of the display image is performed when the degree of matching between the foreground image and the reference image is equal to or greater than a threshold; and an error is determined when the degree of matching between the foreground image and the reference image is below the threshold.

8. The error detection method of claim 7 , wherein the index is a shape index that evaluates a similarity between a shape of the foreground image and the reference image.

9. The error detection method of claim 8 , wherein the foreground image is an image of an icon in the display image, and the reference image is a mask image.

10. The error detection method of claim 7 , wherein the index is stored in an index register.

11. The error detection method of claim 7 , further comprising performing the error detection on the display image, by an error detection circuit, by comparing the index to the threshold.

12. The error detection method of claim 7 , wherein an additional index is obtained, which is separate and distinct from the index and which represents a degree of visibility of the foreground image against a background image of the display image, and the error detection on the display image is performed using both the index and the additional index.